Fix for incorrect handling of BUFSIZE = 0. The handling of aggregations was

flawed in that even without any ECBs with aggregation, the code logic was
assuming there was at least one aggregation (the sentinel in the IDR).  The
handling of the aggregations IDR in the DTrace state has been updated to use
an explicit counter because the IDR functionality does not provide us with an
API function to determine the amount of elements in the IDR.

Signed-off-by: Kris Van Hees <kris.van.hees@oracle.com>

diff --git a/dtrace/dtrace_ecb.c b/dtrace/dtrace_ecb.c
index 96463cccd2b20808f7a45d8638917b2f743d9270..8f91dae89f99505ddd7e6ba8315fe83de383eaa7 100644 (file)
--- a/dtrace/dtrace_ecb.c
+++ b/dtrace/dtrace_ecb.c
@@ -147,6 +147,7 @@ again:
                goto again;
        }
 
+       state->dts_naggs++;
        agg->dtag_id = aggid;
 
        frec = &agg->dtag_first->dta_rec;
@@ -170,6 +171,7 @@ void dtrace_ecb_aggregation_destroy(dtrace_ecb_t *ecb, dtrace_action_t *act)
        ASSERT(DTRACEACT_ISAGG(act->dta_kind));
 
        idr_remove(&state->dts_agg_idr, agg->dtag_id);
+       state->dts_naggs--;
 
        kfree(agg);
 }

diff --git a/dtrace/dtrace_state.c b/dtrace/dtrace_state.c
index 35e186a4209b501325f53d2e1ddcec0a1f62b3d5..91ba3fbe2b8a8fc1f65053871a302961ca74d0b8 100644 (file)
--- a/dtrace/dtrace_state.c
+++ b/dtrace/dtrace_state.c
@@ -339,6 +339,7 @@ dtrace_state_t *dtrace_state_create(struct file *file)
        state->dts_buffer = kzalloc(bufsize, GFP_KERNEL);
        state->dts_aggbuffer = kzalloc(bufsize, GFP_KERNEL);
        idr_init(&state->dts_agg_idr);
+       state->dts_naggs = 0;
        state->dts_cleaner = 0;
        state->dts_deadman = 0;
        state->dts_vstate.dtvs_state = state;
@@ -682,7 +683,7 @@ int dtrace_state_go(dtrace_state_t *state, processorid_t *cpu)
 
        if (opt[DTRACEOPT_AGGSIZE] != DTRACEOPT_UNSET &&
            opt[DTRACEOPT_AGGSIZE] != 0) {
-               if (idr_empty(&state->dts_agg_idr)) {
+               if (state->dts_naggs == 0) {
                        /*
                         * We're not going to create an aggregation buffer
                         * because we don't have any ECBs that contain
@@ -718,7 +719,7 @@ int dtrace_state_go(dtrace_state_t *state, processorid_t *cpu)
 
        if ((state->dts_needed != 0 && opt[DTRACEOPT_BUFSIZE] < sz) ||
            (state->dts_speculates && opt[DTRACEOPT_SPECSIZE] < sz) ||
-           (!idr_empty(&state->dts_agg_idr) && opt[DTRACEOPT_AGGSIZE] < sz)) {
+           (state->dts_naggs != 0 && opt[DTRACEOPT_AGGSIZE] < sz)) {
                /*
                 * A buffer size has been explicitly set to 0 (or to a size
                 * that will be adjusted to 0) and we need the space -- we
@@ -1050,10 +1051,8 @@ void dtrace_state_destroy(dtrace_state_t *state)
         * If there were aggregations allocated, they should have been cleaned
         * up by now, so we can get rid of the idr.
         */
-       if (!idr_empty(&state->dts_agg_idr)) {
-               idr_remove_all(&state->dts_agg_idr);
-               idr_destroy(&state->dts_agg_idr);
-       }
+       idr_remove_all(&state->dts_agg_idr);
+       idr_destroy(&state->dts_agg_idr);
 
        kfree(state->dts_buffer);
        kfree(state->dts_aggbuffer);